The Diocese of Rome commissioned several modern churches to be built to mark the Great Jubilee in 2000. One of these churches, the Chiesa di Dio Padre Misericordioso, was designed by American architect Richard Meier. Completed in 2003, the church represents a stylized ship—a traditional symbol for the universal church of God—while the three concave sails represent the Holy Trinity. The exterior walls are made of self-cleaning concrete to protect them from air pollution.